Recording/reproducing apparatus, recording/reproducing method, medium, and program

ABSTRACT

Continuous transfer of AV data without a break necessitates to perform replacement processing of a disk access unit and takes labor and time.  
     A characteristic is that an HDD  2  is disposed which writes AV data in a recording medium, that an AV recording/reproducing controller  3  is disposed which, when there is a write error in writing of AV data in a disk access unit which is a minimum unit for continuously accessing the recording medium, controls the HDD  2  such that this disk access unit will be skipped and said AV data will be written in the next disk access unit, that skip processing judging means  5  is disposed, and that a replacement area is not formed in the recording medium.

TECHNICAL FIELD

[0001] The present invention relates to a recording and reproducingapparatus, a recording and reproducing method, a medium and a programfor recording AV data.

BACKGROUND ART

[0002] The recent years have seen a proliferating use of recording andreproducing apparatuses, such as hard disk drives and magneto-optic diskdrives, for their large capacities and high speeds as external storageapparatuses, in accordance with dissemination and progresses of personalcomputers. As computer software of larger volumes are used and data tobe handled accordingly become large-volume data, the speeds and thecapacities of these recording and reproducing apparatuses used asexternal storage apparatuses are increasing.

[0003] In this manner, a recording and reproducing apparatus which usedto handle computer data is now used as a digital AV apparatus forrecording and reproducing video and audio data (hereinafter referred toas “AV data”) making the most of their large capacities and high speedand utilizing a digital technology.

[0004] When data, a program or the like for a computer are to berecorded in a recording and reproducing apparatus, an error of even onebit causes a serious problem such as one that the program malfunctions.Hence, a recording and reproducing apparatus executes a strict errorcheck at the time of recording and reproducing of computer data, tothereby guarantee the reliability of data, a program, etc.

[0005] Such error checks include re-allocation processing ofre-allocating an LBA (Logical Block Address) to a sector in a recordingmedium, retry processing of recording in or reading from a sector inwhich there is an error, replacement processing of allocating an LBAallocated to an error-bound sector to other sector within a replacementarea and suspending use of the error-bound sector, etc.

[0006] Meanwhile, when AV data are to be recorded in a recording andreproducing apparatus, it is important to record or reproduce whileensuring that AV data will remain continuous so that the continuity ofthe AV data, rather than the reliability of the data, will beguaranteed.

[0007] In other words, when AV data are to be reproduced, if an erroroccurs in 1-byte data for instance, a resulting influence is merely tothe extent that most of the audience will not notice when such AV dataare displayed on a television monitor.

[0008] However, when a strict error check such as retry processing andreplacement processing is executed during reproduction of the AV data,the reproduction of the AV data will be interrupted by the error checkand images displayed on the television monitor will accordingly bechopped, which is very much disturbing to the audience.

[0009]FIG. 13 shows a proposed recording and reproducing apparatus 40which records and reproduces while guaranteeing the continuity of AVdata.

[0010] The recording and reproducing apparatus 40 is comprised of an HDD41, an AV recording/reproducing HDD controller 43, a replacement DAUtable 42, a file system 4, a recording buffer 8 and a play buffer 9.

[0011]FIG. 14 shows a magnetic disk medium 44 which the HDD 41 writesand reads AV data in and from.

[0012] In the magnetic disk medium 44, there are an AV data recordingarea 47 and a replacement DAU area 46. In short, the AV data recordingarea 47 is an area for writing AV data in disk access units which arethe minimum units for continuously accessing the magnetic disk medium44, whereas the replacement DAU area 46 is an area in which a diskaccess unit is secured in advance which will be used to write AV datainstead of a defective or otherwise inappropriate disk access unitwithin the AV data recording area 47 if it is not possible to writenormally in the defective disk access unit. Thus, the recording andreproducing apparatus 40 executes replacement processing of a diskaccess unit of writing AV data in the disk access unit secured withinthe replacement DAU area 46 as a substitution for a disk access unitwithin the AV data recording area 47.

[0013] Further, when the sizes of the disk access units become small,the HDD 41 is sought for and forced on rotation stand-by frequently, andtherefore, a transfer rate for AV data slows down. Noting this, thesizes of the disk access units are made large enough so as to guaranteecontinuous transfer of AV data, and set to 2 Mbytes for example.

[0014] The HDD 41 is means which holds a table in which a notified LBA(Logical Block Address) is associated with a track number and a sectornumber which express a physical location in the magnetic disk medium 44as shown in FIG. 17, and serves as means which specifies a physicallocation in the magnetic disk medium 44 utilizing this table, and thenwrites or read AV data.

[0015] The AV recording/reproducing HDD controller 43 is means whichcontrols the HDD 41. The replacement DAU table 42 is a table foridentifying a post-replacement disk access unit number from apre-replacement disk access unit number.

[0016]FIG. 15 shows an example of the replacement DAU table 42. A DAUnumber 51 is the number assigned to a disk access unit as it is beforereplacement processing, while a post-replacement DAU number 52 is thenumber assigned to a disk access unit as it is after replacementprocessing. Without replacement processing performed, the same number inthe DAU number 51 is stored as the post-replacement DAU number 52.

[0017] The file system 4 is for handling AV data as a file and serves asmeans which holds file information, which contains information regardingdisk access units which form files, designates file name and refers tothe file information or updates the file information.

[0018] In addition, a DAU converting table 53 is stored in the filesystem 4 as shown in FIG. 16. The DAU converting table 53 is a table forconverting a disk access unit number 54 assigned to specify a diskaccess unit into an LBA 55 which is at the top of a disk access unitwithin the magnetic disk medium 44.

[0019] The recording buffer 8 is a buffer which, upon transfer of AVdata to be written in the magnetic disk medium 44, temporarily storesthe AV data.

[0020] The recording buffer 8 is a buffer which temporarily stores AVdata which were read from the magnetic disk medium 44.

[0021] Operations of such a recording and reproducing apparatus 40 willnow be described.

[0022] First, the recording and reproducing apparatus 40 formats themagnetic disk medium 44, prior to recording or reproduction of AV datain or from the magnetic disk medium 44. At the time of the formattingprocessing, the replacement DAU area 46 is also ensured separately fromthe AV data recording area 47.

[0023] Next, replacement processing is performed which is for replacinga disk access unit which is defective or requires a predetermined periodof time or longer time for writing or reading with a disk access unitwhich is within the replacement DAU area 46 so as to guarantee real-timetransfer of AV data.

[0024] That is, writing in a disk access unit or reading from a diskaccess unit within the magnetic disk medium 44, the AVrecording/reproducing HDD controller 43 identifies a disk access unitwhich is defective or requires a predetermined period of time or longertime for writing or reading.

[0025] When identifying such a disk access unit, the AVrecording/reproducing HDD controller 43 notifies the file system 4 ofthis.

[0026] Upon notification, the file system 4 rewrites the replacement DAUtable 42. In short, the post-replacement DAU number 52 which correspondsto the number assigned to the disk access unit thus notified about isrewritten into the number assigned to a disk access unit which is withinthe replacement DAU area 46.

[0027] The processing above will then be repeated for all disk accessunits which are within the replacement DAU area 46.

[0028] When replacement processing is performed in the units of sectors,since a seek action and rotation stand-by occur in a sector which isunder the replacement processing, writing and reading take an extraamount of time. Hence, replacement processing at smaller intervals thana size which guarantees continuous transfer of AV data makes itimpossible to guarantee continuous transfer of the AV data because ofseek, rotation stand-by, etc. On the contrary, the recording andreproducing apparatus 40, executing replacement processing in the unitsof disk access units whose sizes guarantees continuous transfer of AVdata, can guarantee the continuity of the AV data even at the time ofreplacement processing.

[0029] In this manner, the recording and reproducing apparatus 40performs replacement processing in the units of disk access units inadvance and therefore guarantees transfer of AV data in real time.

[0030] Recording of AV data in the magnetic disk medium 44 will now bedescribed.

[0031] AV data received by a television tuner or the like aretransferred to the recording and reproducing apparatus 40 in real time.

[0032] The recording buffer 8 temporarily records the AV data thustransferred in real time.

[0033] Storing the AV data amounting to a disk access unit, therecording buffer 8 notifies the AV recording/reproducing HDD controller43 of that.

[0034] Notified by the recording buffer 8 of the storage of the AV dataamounting to a disk access unit, the AV recording/reproducing HDDcontroller 43 demands the file system 4 to tell in which disk accessunit the AV data will be written.

[0035] In response, the file system 4 checks, from the file information,the number assigned to a disk access unit in which AV data are to bewritten, and using the replacement DAU table 42 shown in FIG. 15,converts the disk access unit number 51 into the post-replacement DAUnumber 52. In the event that the disk access unit in which AV data areto be written has been replaced because of a defect or the like, thedisk access unit number of the replacement DAU area 46 is written as thepost-replacement DAU number 52. In the event that no replacementprocessing is performed, the number which is the same as the numberassigned to the disk access unit in which AV data are to be written iswritten as the post-replacement DAU number 52. The number assigned tothe replaced disk access unit is then reported to the AVrecording/reproducing HDD controller 43. Hence, of the disk access unitswithin the AV data recording area 47, a disk access unit which isdefective or requires a predetermined period of time or longer time forwriting or reading is not used.

[0036] Notified by the file system 4 of the number assigned to thereplaced disk access unit to which AV data is written, the AVrecording/reproducing HDD controller 43 demands for notification of thetop LBA of thus notified disk access unit number.

[0037] Upon receipt of the demand from the AV recording/reproducing HDDcontroller 43, the file system 4 identifies the disk access unit numberand the LBA at the top of the disk access unit denoted as the top LBA 55while referring to the DAU converting table 53 which is shown in FIG.16, and notifies the AV recording/reproducing HDD controller 43 of thesame.

[0038] Further, the AV recording/reproducing HDD controller 43 demandsthe recording buffer 8 to transfer AV data to be written in one diskaccess unit.

[0039] In response, the recording buffer 8 transfers AV data to bewritten in one disk access unit to the AV recording/reproducing HDDcontroller 43.

[0040] The AV recording/reproducing HDD controller 43 designates, fromthe notified LBA, the number of sectors in which AV data are to bewritten, issues a write command to the file system 4, and transfers theAV data transferred from the recording buffer 8 to the HDD 41.

[0041] The file system 4 provides the HDD 41 with the write commandwrite command sent from the AV recording/reproducing HDD controller 43.

[0042] The HDD 41 converts the notified LBA into a track number and asector number with reference to the table which is shown in FIG. 17, andwrites the transferred AV data in a sector which forms a correspondingtrack which is in the magnetic disk medium 44.

[0043] Meanwhile, AV data are transferred to the recording buffer 8 inreal time, and the recording buffer 8, upon storing the AV dataamounting to a disk access unit, notifies the AV recording/reproducingHDD controller 43 of that. Operations similar to the above will then berepeated, thereby recording the AV data transferred in real time. Thisprevents use of a disk access unit which will not see a termination ofrecording of AV data even after a predetermined period of time or longertime due to a defect or the like, and therefore, it is possible toguarantee real-time transfer of AV data.

[0044] Reading of AV data from the magnetic disk medium 44 will now bedescribed.

[0045] The play buffer 9 outputs AV data in real time, and when a freespace is created which amounts to a disk access unit, notifies the AVrecording/reproducing HDD controller 43 of that.

[0046] Notified from the play buffer 9, the AV recording/reproducing HDDcontroller 43 demands the file system 4 for the number assigned to adisk access unit which is to be read out next.

[0047] In response, the file system 4 checks from the file informationthe number assigned to a disk access unit in which AV data are to bewritten, and converts the disk access unit number 51 into thepost-replacement DAU number 52 with reference to the replacement DAUtable 42. Hence, a defective disk access unit will not be used. The AVrecording/reproducing HDD controller 43 is then notified of the numberassigned to a replaced disk access unit.

[0048] When notified by the file system 4 of the number assigned to thedisk access unit in which AV data are to be written, the AVrecording/reproducing HDD controller 43 makes an inquiry regarding thetop LBA of the disk access unit thus reported to the file system 4.

[0049] Receiving the inquiry from the AV recording/reproducing HDDcontroller 43, the file system 4 notifies the AV recording/reproducingHDD controller 43 of the top LBA of the disk access unit.

[0050] The AV recording/reproducing HDD controller 43, upon notificationby the file system 4 of the notified LBA, designates the LBA and thenumber of sectors in which the AV data are to be read out and issues aread command to the file system 4.

[0051] The file system 4 relays the read command sent from the AVrecording/reproducing HDD controller 43 to the HDD 41.

[0052] The HDD 41 converts the notified LBA into a track number and asector number with reference to the table which is shown in FIG. 17, andreads the AV data from the sectors which form a corresponding trackwhich is in the magnetic disk medium 44 and transfers to the AVrecording/reproducing HDD controller 43.

[0053] The AV recording/reproducing HDD controller 43 transfers thusread AV data to the play buffer 9.

[0054] The play buffer 9 stores the AV data read by the AVrecording/reproducing HDD controller 43 and outputs stored AV data inreal time.

[0055] Hence, since the sizes of the disk access units are made largeenough so as to continuously transfer AV data, and further, since a diskaccess unit which is within the replacement DAU area 46 is used insteadof a defective disk access unit, the recording and reproducing apparatus40 guarantees continuous transfer of the AV data.

[0056] However, requiring to execute replacement processing of a diskaccess unit in advance in order to guarantee continuous transfer of AVdata, the conventional recording and reproducing apparatus 40 needslabor and time.

[0057] That is, it is necessary to execute replacement processing of adisk access unit for the purpose of continuously transferring AV data,which gives rise to a problem that it takes labor and time (firstproblem).

[0058] Further, at the time of replacement processing, reading andwriting are executed in the entire magnetic disk medium 44 in order tofind a defect in a disk access unit or a disk access unit which requiresa predetermined period of time or longer time for writing or reading,and hence, AV data already recorded in the magnetic disk medium 44 getdeleted.

[0059] In other words, there is a problem (second problem) thatreplacement processing of a disk access unit executed for the purpose ofcontinuously transferring AV data causes deletion of AV data which werepreviously recorded in a recording medium.

[0060] In addition, for execution of replacement processing of a diskaccess unit, it is necessary to secure a disk access unit in themagnetic disk medium 44 which will serve as a substitute like thereplacement DAU area 46. Because of this, an area such as the AV datarecording area 47 in which a user-can freely record AV data decreases.

[0061] That is, there is a problem (third problem) that for execution ofreplacement processing of a disk access unit for the purpose ofguaranteeing continuous transfer of AV data without a break, it isnecessary to secure in advance a disk access unit which will serve as asubstitute, and hence, as compared with where replacement processing isnot carried out, an area which a user can freely use decreases.

[0062] Further, in the event that there is disturbance such asvibrations, even though there is not a defect in a disk access unitwithin the magnetic disk medium 44, the disk access unit will bedetermined defective. Until re-formatting, the disk access unit will betreated as a defective disk access unit.

[0063] That is, there is a problem (fourth problem) that when there isdisturbance such as vibrations, even a disk access unit having no defectis determined as a defective disk access unit and will be treated as adefective disk access unit until the recording medium has beenformatted.

DISCLOSURE OF THE INVENTION

[0064] Considering the first problem described above, the presentinvention aims at providing a recording and reproducing apparatus, arecording and reproducing method, a medium and a program with which itis possible to continuously transfer AV data without a break withouttaking labor and time.

[0065] Further, considering the second problem described above, thepresent invention aims at providing a recording and reproducingapparatus, a recording and reproducing method, a medium and a programwith which it is possible to continuously transfer AV data without abreak without deleting AV data already recorded in a recording medium.

[0066] Further, considering the third problem described above, thepresent invention aims at providing a recording and reproducingapparatus, a recording and reproducing method, a medium and a programwith which it is possible to continuously transfer AV data without abreak without decreasing an area which a user can freely use.

[0067] Further, considering the fourth problem described above, thepresent invention aims at providing a recording and reproducingapparatus, a recording and reproducing method, a medium and a programwith which it is possible to avoid permanently treating a defect-freedisk access unit as a defective disk access unit due to disturbance suchas vibrations and to accordingly re-use such a defect-free disk accessunit.

[0068] To solve the above problems, a first invention of the presentinvention (corresponding to claim 1) is a recording and reproducingapparatus, comprising:

[0069] recording means which writes AV data in or reads AV data from arecording medium; and

[0070] recording control means which, when there is a write error inwriting of AV data in a disk access unit which is a minimum unit forcontinuously accessing said recording medium, controls said recordingmeans such that this disk access unit will be skipped and said AV datawill be written in the next disk access unit,

[0071] wherein a replacement area which corresponds to said disk accessunit in which there is said error is not formed in said recordingmedium.

[0072] A second invention of the present invention (corresponding toclaim 2) is the recording and reproducing apparatus of the firstinvention of the present invention, comprising error judging means whichmakes a judgment regarding whether said write error has occurred,

[0073] wherein said recording control means controls said recordingmeans based on said judgment.

[0074] A third invention of the present invention (corresponding toclaim 3) is the recording and reproducing apparatus of the secondinvention of the present invention, wherein said error judging meansmakes a judgment regarding whether there is a read error in reading ofAV data from said disk access unit, and

[0075] when there is a read error in reading of AV data in said diskaccess unit, said recording control means controls said recording meansbased on said judgment such that this disk access unit will be skippedand AV data will be read from the next disk access unit.

[0076] A fourth invention of the present invention (corresponding toclaim 4) is the recording and reproducing apparatus of the second or thethird invention of the present invention, wherein said error judgingmeans judges that said write error or said read error has occurred whena command error occurs.

[0077] A fifth invention of the present invention (corresponding toclaim 5) is the recording and reproducing apparatus of the second or thethird invention of the present invention, wherein said error judgingmeans judges that said write error or said read error has occurred wheneven after a timer over period derived from the continuity of AV datahas passed, writing or reading of said AV data in said disk access unitfails to complete.

[0078] A sixth invention of the present invention (corresponding toclaim 6) is the recording and reproducing apparatus of the seventhinvention of the present invention, wherein when writing or reading ofsaid AV data in said disk access unit fails to complete even after saidtimer over period, said recording control means forcibly terminates acommand issued to said recording means and accordingly controls suchthat said disk access unit will be skipped.

[0079] A seventh invention of the present invention (corresponding toclaim 7) is the recording and reproducing apparatus of the firstinvention of the present invention, comprising a write skip counterwhich counts the number of times that said disk access unit is skipped,

[0080] wherein said recording control means controls such that when saidnumber of times exceeds a predetermined value which is equal to orlarger than 1, this disk access unit will not be used after this.

[0081] An eighth invention of the present invention (corresponding toclaim 8) is the recording and reproducing apparatus of the seventhinvention of the present invention, wherein the number of times countedby said write skip counter is not initialized unless said recordingmedium is formatted.

[0082] A ninth invention of the present invention (corresponding toclaim 9) is the recording and reproducing apparatus of the firstinvention of the present invention, comprising a read protection flagwhich expresses whether to prohibit reading from said disk access unit,

[0083] wherein when said read protection flag which corresponds to saiddisk access unit is ON, said recording control means controls such thatreading from this disk access unit will not be executed, but

[0084] controls such that reading from this disk access unit will beexecuted when said read protection flag which corresponds to said diskaccess unit is OFF.

[0085] A tenth invention of the present invention (corresponding toclaim 10) is the recording and reproducing apparatus of the ninthinvention of the present invention, wherein when said write error hasoccurred during writing of said AV data in said disk access unit, saidrecording control means turns on said read protection flag whichCorresponds to said disk access unit.

[0086] An eleventh invention of the present invention (corresponding toclaim 11) is the recording and reproducing apparatus of the ninthinvention of the present inveniton, comprising a read skip counter whichcounts the number of times that a read error has occurred during readingof said AV data from said disk access unit,

[0087] wherein when said number of times exceeds a predetermined value,said recording control means turns on said read protection flag whichcorresponds to said disk access unit.

[0088] A twelfth invention of the present invention (corresponding toclaim 12) is the recording and reproducing apparatus of the eleventhinvention of the present inveniton, wherein when writing of said AV datain said disk access unit has ended normally, said recording controlmeans turns off said read protection flag which corresponds to said diskaccess unit, and

[0089] the value of said read skip counter which corresponds to saiddisk access unit is initialized to zero.

[0090] A thirteenth invention of the present invention (corresponding toclaim 13) is the recording and reproducing apparatus of the eleventhinvention of the present invention, wherein when said AV data recordedin said disk access unit are deleted, said recording control means turnsoff said read protection flag which corresponds to said disk accessunit, and

[0091] the value of said read skip counter which corresponds to saiddisk access unit is initialized.

[0092] A fourteenth invention of the present invention (corresponding toclaim 14) is a recording and reproducing method, comprising:

[0093] a recording step of writing AV data in or reading AV data from arecording medium; and

[0094] a recording control step of, when there is a write error inwriting of AV data in a disk access unit which is a minimum unit forcontinuously accessing said recording medium, controlling said recordingstep such that this disk access unit will be skipped and said AV datawill be written in the next disk access unit,

[0095] wherein a replacement area which corresponds to said disk accessunit in which there is said error is not formed in said recordingmedium.

[0096] A fifteenth invention of the present invention (corresponding toclaim 15) is the recording and reproducing method of the fourteenthinvention of the present inveniton, comprising an error judging step ofmaking a judgment regarding whether said write error has occurred,

[0097] wherein said recording control step controls said recording stepbased on said judgment.

[0098] A sixteenth invention of the present invention (corresponding toclaim 16) is the recording and reproducing method of the fifteenthinvention of the present inveniton, wherein said error judging stepmakes a judgment regarding whether there is a read error in reading ofAV data from said disk access unit is judged, and

[0099] when there is a read error in reading of AV data in said diskaccess unit, said recording control step controls said recording meansbased on said judgment such that this disk access unit will be skippedand AV data will be read from the next disk access unit.

[0100] A seventeenth invention of the present invention (correspondingto claim 17) is the recording and reproducing method of the fifteenth orthe sixteenth invention of the present invention, wherein said errorjudging step judges that said write error or said read error hasoccurred when a command error occurs.

[0101] An eighteenth invention of the present invention (correspondingto claim 18) is the recording and reproducing method of the fifteenth orthe sixteenth invention of the present invention, wherein said errorjudging step judges that said write error or said read error hasoccurred when even after a timer over period derived from the continuityof AV data has passed, writing or reading of said AV data in said diskaccess unit fails to complete.

[0102] A nineteenth invention of the present invention (corresponding toclaim 19) is a medium which can be processed on a computer and whichstores a program for making a computer function as all or some of:recording means of the recording and reproducing apparatus of claim 1which writes AV data in or reads AV data from a recording medium; and

[0103] recording control means of the recording and reproducingapparatus of the first invention of the present invention which controlssaid recording means which, when there is a write error in writing of AVdata in a disk access unit which is a minimum unit for continuouslyaccessing said recording medium, controls said recording means such thatthis disk access unit will be skipped and said AV data will be writtenin the next disk access unit.

[0104] A twentieth invention of the present invention (corresponding toclaim 20) is a program for making a computer function as all or some of:recording means of the recording and reproducing apparatus of the firstinvention of the present invention which writes AV data in or reads AVdata from a recording medium; and

[0105] recording control means of the recording and reproducingapparatus of the first invention of the present invention which controlssaid recording means which, when there is a write error in writing of AVdata in a disk access unit which is a minimum unit for continuouslyaccessing said recording medium, controls said recording means such thatthis disk access unit will be skipped and said AV data will be writtenin the next disk access unit.

BRIEF DESCRIPTION OF THE DRAWINGS

[0106]FIG. 1 is a drawing which shows a structure of a recording andreproducing apparatus according to a first embodiment of the presentinvention;

[0107]FIG. 2 is a drawing which shows a structure of the recording andreproducing apparatus according to the first embodiment of the presentinvention for recording in and reproducing from a DVD;

[0108]FIG. 3 is a drawing which shows a structure of the recording andreproducing apparatus according to the first embodiment of the presentinvention for recording in and reproducing from a magneto-optic disk;

[0109]FIG. 4 is a drawing which shows a structure of a recording andreproducing apparatus according to a second embodiment of the presentinvention;

[0110]FIG. 5 is a drawing which shows an example of a magnetic diskmedium according to the first embodiment of the present invention;

[0111]FIG. 6 is a drawing which shows an example of a magnetic diskmedium as it is when AV data are deleted according to the firstembodiment of the present invention;

[0112]FIG. 7 is a flow chart which shows operations of error monitoringmeans according to the first embodiment of the present invention;

[0113]FIG. 8 is a flow chart which shows operations of skip processingjudging means during recording according to the first embodiment of thepresent invention;

[0114]FIG. 9 is a flow chart which shows operations of the skipprocessing judging means during reproduction according to the firstembodiment of the present invention;

[0115]FIG. 10 is another flow chart which shows operations of the skipprocessing judging means during reproduction according to the firstembodiment of the present invention;

[0116]FIG. 11 is a flow chart which shows operations of the skipprocessing judging means during reproduction according to the secondembodiment of the present invention;

[0117]FIG. 12 is a flow chart which shows operations of the recordingand reproducing apparatus during deletion of AV data according to thefirst embodiment of the present invention;

[0118]FIG. 13 is a drawing which shows a structure of a conventionalrecording and reproducing apparatus;

[0119]FIG. 14 is a drawing which shows an example of a magnetic diskmedium which the conventional recording and reproducing apparatusrecords in and reproduces from;

[0120]FIG. 15 is a drawing which shows an example of a replacement DAUtable of the conventional recording and reproducing apparatus;

[0121]FIG. 16 is a drawing which shows an example of a DAU conversiontable which is used by the conventional recording and reproducingapparatus and the recording and reproducing apparatuses according to theembodiments; and

[0122]FIG. 17 is a drawing which shows a table which associates an LBAwith a physical address, which is used by the conventional recording andreproducing apparatus and the recording and reproducing apparatusesaccording to the embodiments.

[0123]1 recording and reproducing apparatus

[0124]2 HDD

[0125]3 AV recording/reproducing HDD controller 3

[0126]4 file system

[0127]5 skip processing judging means

[0128]6 error monitoring means

[0129]7 timer

[0130]8 recording buffer

[0131]9 play buffer

[0132]11 recording and reproducing apparatus

[0133]12 DVD RAM drive

[0134]13 AV recording/reproducing DVD controller

[0135]14 recording and reproducing apparatus

[0136]15 MO drive

[0137]16 AV recording/reproducing MO controller

[0138]17 recording and reproducing apparatus

[0139]18 AV recording/reproducing controller

[0140]20 magnetic disk medium

[0141]22 usable defective DAU

[0142]23 unusable defective DAU

[0143]26 AV data recording area

[0144]27 magnetic disk medium

BEST MODE FOR IMPLEMENTING THE INVENTION

[0145] With reference to the associated drawings, embodiments will nowbe described which are the best mode for implementing the presentinvention.

[0146] (FIRST EMBODIMENT)

[0147] First, a first embodiment will now be described.

[0148]FIG. 1 shows a recording and reproducing apparatus 1 according tothis embodiment.

[0149] The recording and reproducing apparatus 1 comprises and HDD2, anAV recording/reproducing HDD controller 3, a file system 4, skipprocessing judging means 5, error monitoring means 6, a timer 7, arecording buffer 8 and a play buffer 9.

[0150] The HDD 2 is, as shown in FIG. 17, means which stores orassociating a notified LBA (Logical Block Address) with a track numberand a sector number expressing a physical location in a magnetic diskmedium in a similar manner that according to the conventional technique,and associates an LBA with a track number and a sector number in amagnetic disk medium while utilizing this table and writes AV data in orreads AV data from the magnetic disk medium.

[0151]FIG. 5 shows a magnetic disk medium 20 which the HDD 2 writes AVdata in or reads AV data from. Unlike the magnetic disk medium 44described in relation to the conventional technique, the magnetic diskmedium 20 does not include a replacement DAU area 46.

[0152] The AV recording/reproducing HDD controller 3 is means whichcontrols the HDD 2.

[0153] The file system 4 is means which manages files, disk access unitsand the like while using a DAU conversion table which is for identifyingan LBA located at the top of a disk access unit from file information,which is information regarding files recorded in the HDD 2, informationregarding the respective disk access units in the magnetic disk medium20 and the numbers assigned to the disk access units.

[0154] The file information herein referred to is informationexpressing, from a file name, in which disk access units and in whichorder AV data are written, and permitting for instance to associate afile name to the numbers assigned to the disk access units which formthe corresponding file and list up the numbers assigned to the diskaccess units in the order in which the AV data are written.

[0155] Meanwhile, the information regarding the respective disk accessunits in the magnetic disk medium 20 includes a write skip counter whichcounts the number of times that writing in every disk access unit hasbeen skipped, a read skip counter which counts the number of times thatreading from disk access unit has been skipped, a bad DAU flag whichindicates that AV data will not be read out from a disk access unitduring reading, etc.

[0156]FIG. 16 shows a DAU converting table 53. The DAU converting table53 is a table is for converting a disk access unit number 54 assigned tospecify a disk access unit into an LBA 55 which is at the top of a diskaccess unit within the magnetic disk medium 44.

[0157] The skip processing judging means 5 is means which judges whetherto skip a disk access unit during writing or reading.

[0158] The error monitoring means 6 is means which monitors whether awrite or read error has occurred while writing in or reading from a diskaccess unit is ongoing.

[0159] The timer 7 is means which measures a period of time during whichwriting in or reading from a disk access unit is ongoing.

[0160] The recording buffer 8 is a buffer which temporarily stores AVdata when the AV data to be written in the HDD 2 are transferred to therecording buffer 8.

[0161] The play buffer 9 is a buffer which temporarily stores AV dataread out from the HDD 2.

[0162] The HDD 2 according to this embodiment is an example of recordingmeans of the present invention, the magnetic disk medium 20 according tothis embodiment is an example of a recording medium of the presentinvention, the AV recording/reproducing HDD controller 3 and the skipprocessing judging means 5 according to this embodiment are an exampleof recording control means of the present invention, the errormonitoring means 6 according to this embodiment is an example of errormonitoring means of the present invention, the bad DAU flag according tothis embodiment is an example of a read protection flag, and the errormonitoring means 6 according to this embodiment is an example ofreading-out error monitoring means of the present invention.

[0163] Operations of such a recording and reproducing apparatus 1 willnow be described. First, a description will be given on operations for asituation that AV data are to be recorded in the magnetic disk medium 20within the HDD 2.

[0164] Upon formatting of the magnetic disk medium 20, the write skipcounter and the read skip counter of each disk access unit describedabove are both initialized to zero and the bad DAU flag is set to OFF.The bad DAU flag being OFF means that AV data are to be read out from acorresponding disk access unit, while the bad DAU flag being ON meansthat AV data are not to be read out from the disk access unit.

[0165] The file information which the file system 4 uses for managementof the files, the information regarding the disk access units and theDAU converting table 53, are stored in the magnetic disk medium 20. Whenthe recording and reproducing apparatus 1 is started up, the file system4 loads the file information, the information regarding the disk accessunits and the DAU converting table 53 into a memory of the file system 4from the magnetic disk medium 20.

[0166] AV data received by a television tuner or the like aretransferred to the recording and reproducing apparatus 1 in real time.

[0167] The recording buffer 8 temporarily stores the AV data thustransferred in real time. Storing the AV data amounting to a disk accessunit, the recording buffer 8 notifies the AV recording/reproducing HDDcontroller 3 of the storage of the AV data amounting to a disk accessunit.

[0168] Notified by the recording buffer 8 of the storage of the AV dataamounting to a disk access unit, the AV recording/reproducing HDDcontroller 3 demands the file system 4 to tell which disk access unitthe AV data will be written.

[0169] In response, the file system 4 notifies the AVrecording/reproducing HDD controller 3 of the number assigned to thedisk access unit in which AV data are to be written from the fileinformation.

[0170] Notified by the file system 4 of the number assigned to the diskaccess unit in which AV data are to be written, the AVrecording/reproducing HDD controller 3 makes an inquiry regarding thetop LBA of the number assigned to the disk access unit thus notifiedabout to the file system 4.

[0171] Receiving the inquiry from the AV recording/reproducing HDDcontroller 3, the file system 4 obtains the LBA at the top of the diskaccess unit denoted as the top LBA 55 according to the disk access unitnumber, using the DAU converting table 53 which is shown in FIG. 16, andnotifies the AV recording/reproducing HDD controller 3 of the same.

[0172] Further, the AV recording/reproducing HDD controller 3 demandsthe recording buffer 8 to transfer AV data which are to be written inone disk access unit.

[0173] In response, the recording buffer 8 transfers AV data to bewritten in one disk access unit to the AV recording/reproducing HDDcontroller 3.

[0174] The AV recording/reproducing HDD controller 3 transfers to theHDD2 the AV data thus transferred from the recording buffer 8,designates the LBA 55 at the top of the disk access unit and a writesize which is the size of one disk access unit and issues a writecommand to the file system 4. The file system 4 relays the write commandsent from the AV recording/reproducing HDD controller 3 to the HDD 2.

[0175] The HDD 2 converts the notified LBA into a track number and asector number with reference to the table which is shown in FIG. 17, andwrites the transferred AV data in a corresponding sector within themagnetic disk medium 44.

[0176] Meanwhile, AV data are transferred to the recording buffer 8 inreal time, and the recording buffer 8, upon storing the AV dataamounting to a disk access unit, notifies the AV recording/reproducingHDD controller 3 of that again. The recording and reproducing apparatus1 repeats operations similar to those described above, therebysequentially recording AV data which are transferred in real time ineach disk access unit.

[0177] As described above, for recording of AV data, the errormonitoring means 6 monitors whether a write command issued by the AVrecording/reproducing HDD controller 3 is executed normally or an errorhas occurred, and accordingly detects a defective disk access unit.

[0178]FIG. 7 shows operations of the error monitoring means 6. Theoperations of the error monitoring means 6 will now be described withreference to FIG. 7.

[0179] When the AV recording/reproducing HDD controller 3 issues a writecommand in the manner described above (S1) the error monitoring means 6starts error monitoring. In other words, using the timer 7, an elapsedtime since the issuance of the write command by the AVrecording/reproducing HDD controller 3 is measured.

[0180] The error monitoring means 6 determines whether a notification ofend of write command has been sent from the HDD 2 (S2). When thenotification of end of write command is yet to be received from the HDD2, the error monitoring means 6 proceeds to S4, but to S3 when thenotification of end of write command has been sent from the HDD 2.

[0181] At S4, the error monitoring means 6 determines whether an elapsedtime since the issuance of the write command is 300 msec or longer. Theperiod of time 300 msec is a time over period which is yielded from thecontinuity of AV data. That is, in the event that writing in one diskaccess unit ends in 300 msec or shorter time, it is possible toguarantee the continuity of AV data which are to be written. A method ofderiving the timer over period will be described later. When it is 300msec or more since the issuance of the write command, the errormonitoring means 6 proceeds to S5, but to S2 when it is 300 msec orless.

[0182] In the event that an elapsed time of 300 msec or more has elapsedsince the issuance of the write command, the error monitoring means 6 atS5 instructs the AV recording/reproducing HDD controller 3 to interruptthe writing. Provided with the instruction from the error monitoringmeans 6, the AV recording/reproducing HDD controller 3 issues a writeinterrupt command to the file system 4, and the file system 4 relays thewrite interrupt command to the HDD 2. Receiving the write interruptcommand, the HDD 2 interrupts the writing and proceeds to S6.

[0183] At S6, the error monitoring means 6 notifies the skip processingjudging means 5 of detection of a defective disk access unit. The skipprocessing judging means 5, notified by the error monitoring means 6 ofdetection of a defective DAU, starts up skip processing. The skipprocessing will be described later.

[0184] Meanwhile, at S3, when notifying of the end of the write command,the HDD 2 notifies whether the write command was ended normally orbecause of an error. Upon receipt of the notification of end of writecommand from the HDD 2, the error monitoring means 6 judges whether thewrite command was ended normally or because of an error.

[0185] When the write command was ended because of an error, the errormonitoring means 6 proceeds to S6, but to S7 when the write command wasended normally.

[0186] In short, at S6, in the event that the write command was endedbecause of an error or in the event that the write command was not endedeven after 300 msec, the error monitoring means 6 determines that thedisk access unit in which writing of the AV data was tried is adefective disk access unit, on the basis that a write error hasoccurred.

[0187] At S7, in the event that the write command was ended normally,the error monitoring means 6 notifies the skip processing judging means5 of a normal termination of the write command, and the AVrecording/reproducing HDD controller 3 issues the next write commandwhen notified by the recording buffer 8 of storage of AV data amountingto the next disk access unit.

[0188] Operations of the skip processing judging means 5 will now bedescribed. FIG. 8 shows operations of the skip processing judging means5.

[0189] At S10, when notified by the error monitoring means 6, the skipprocessing judging means 5 judges whether this notification is anotification of a normal termination of a write command or anotification of detection of a defective disk access unit (S11).

[0190] When the notification is a notification of detection of adefective disk access unit, the skip processing judging means 5 proceedsto S12, but to S15 when the notification is a notification of a normaltermination of the write command.

[0191] At S15, the skip processing judging means 5, notified of a normaltermination of the write command, initializes a write skip flag of acorresponding disk access unit to zero, turns off a bad DAU flag, andproceeds to S16.

[0192] On the contrary, at S12, the skip processing judging means 5,notified by the error monitoring means 6 of detection of a defectivedisk access unit, increments the write skip counter of the disk accessunit only by 1.

[0193] After turning on the bad DAU flag of the disk access unit (S13),the skip processing judging means 5 proceeds to S16.

[0194] At S16, the skip processing judging means 5 acquires the numberassigned to a disk access unit which needs be written next from the filesystem 4, treats this as a current disk access unit and proceeds to S17.

[0195] At S17, the skip processing judging means 5 determines whetherthe current disk access unit is permanently defective. That is, the skipprocessing judging means 5 recognizes a permanent defect when the valueof the write skip counter of the current disk access unit is over 5, butdoes not recognize a permanent defect when the value is 5 or smaller. Apermanently defective disk access unit refers to such a disk access unitin which it is not possible to write or read normally not because ofdisturbance such as vibrations but because of a defect of the diskaccess unit itself.

[0196] A method of judging a permanent defect will now be described.Causes of a write error and a read error in the recording andreproducing apparatus 1 include an error attributed to a defect in adisk, an error attributed to a random error, an error attributed todisturbance such as vibrations, etc.

[0197] Of these, an error attributed to a defect in a disk is an errorassociated with a defect in a disk access unit of the magnetic diskmedium 20 within the HDD 2, which always occurs during reading from adefective disk access unit and also during writing in a similar fashion.On the other hand, an error attributed to a random error is an errorwhich occurs because of a random access to a disk access unit, and aprobability of an error attributed to a random error is as small asabout 10⁻¹². An error attributed to disturbance such as vibrations andthe like occurs differently in different environments of use but at anempirical probability of about 10⁻⁹ in normal installment in ahousehold.

[0198] A permanently defective disk access unit is a disk access unit inwhich there is a defect of the disk access unit itself as describedearlier, and every time such a disk access unit is written in or read,an error occurs. Hence, when a probability of an error occurring duringwriting in or reading from a certain disk access unit is higher than aprobability of an error attributed to a random error and a probabilityof an error attributed to disturbance such as vibrations, etc., it ispossible to determine that this disk access unit is a permanentlydefective disk access unit. When a probability of an error occurringduring writing or reading is larger than 10−9, therefore, it is possibleto determine that this disk access unit is a permanently defective diskaccess unit.

[0199] To be more specific, in a condition that a user's usage is use ofthe recording and reproducing apparatus 1 for five years, the magneticdisk medium 20 of the HDD 2 has a capacity of 30 Gbytes, the size ofdisk access units of the magnetic disk medium 20 is 1 Mbyte andrecording of 24 Mbps of data is continued for eight hours a day, onedisk access unit is written twice a day on the average. Hence, duringfive years, on the average, one disk access unit is written 2×365×5=3650 times. During writing over 3650 times in a certain disk accessunit, therefore, the frequency of an error other than a defect of thedisk is barely one time. In short, an error attributed to disturbancesuch as vibrations occurs about only once in five years in one diskaccess unit, while an error attributed to a random error occurs aboutonly once in ten years.

[0200] Hence, in this model, as for detection of a permanent error, itis possible to judge that errors occurring twice is an error attributedto a defect of the disk. In other words, in this model, a permanentdefect is recognized when the value of the write skip counter of thecurrent disk access unit is over 1 while a permanent defect is notrecognized when the value is equal to or smaller than 1, thereby judgingwhether the disk access unit is permanently defective. In this manner,it is possible to judge whether a disk access unit is permanentlydefective by recognizing a permanent defect when the value of the skipcounter is beyond a predetermined value (which is 1 in this model) whilenot recognizing a permanent defect when the value is equal to or smallerthan the predetermined value. Further, since a judgment regarding anerror attributed to a defect of the disk is different depending on thecondition of use and an error characteristic of a medium, it isnecessary to determine the predetermined value which is used forrecognition of a permanent defect in advance in accordance withapplications. At S17, 5 is used as such a predetermined value,considering that some disk access units of the magnetic disk medium 20within the HDD 2 could be more frequently written in or read than otherdisk access units.

[0201] When the current disk access unit is permanently defective atS17, the skip processing judging means 5 proceeds to S16. When thecurrent disk access unit is not permanently defective, the skipprocessing judging means 5 notifies the AV recording/reproducing HDDcontroller 3 of the number assigned to the disk access unit to beskipped and proceeds to S18. That is, the disk access unit judgedpermanently defective will not be used after this.

[0202] For example, in the magnetic disk medium 20 shown in FIG. 5, ausable defective DAU 22 is one for which the value of the write skipcounter is 5 or smaller, and writing in such a disk access unit isexecuted. However, an usable defective DAU 23 is one for which the valueof the write skip counter is over 5, and writing in such a disk accessunit is not executed.

[0203] At S18, the AV recording/reproducing HDD controller 3 is notifiedby the recording buffer 8 of storage of AV data which are to be writtenin the next disk access unit and amount to a disk access unit, and theAV recording/reproducing HDD controller 3 skips a disk access unit ofwhich the skip processing judging means 5 notified to skip, acquires thenumber assigned to the disk access unit which needs be written in nextfrom the file system 4 and proceeds to S19.

[0204] At S19, the AV recording/reproducing HDD controller 3 issues awrite command which is for writing in the next disk access unit to theHDD 2 via the file system 4.

[0205] In this manner, the recording and reproducing apparatus 1 writesAV data in the disk access units of the magnetic disk medium 20 oneafter another.

[0206] As described above, the recording and reproducing apparatus 1according to this embodiment increments the write skip counter of anerror-bound disk access unit only by 1, and turns on the bad DAU flag.AV data are then written in the disk access unit which needs be writtenafter this disk access unit. A disk access unit for which the value ofthe write skip counter is over 5 is regarded permanently defective, andwill not be written with AV data.

[0207] The bad DAU flag of a disk access unit is turned off when writingin the disk access unit succeeds even once, and the read skip counter iszeroed. In this case, the write skip counter is left as it is.

[0208] Hence, unlike according to the conventional technique, therecording and reproducing apparatus 1 according to this embodiment iscapable of continuously transferring AV data without executingreplacement processing. Further, it is possible to re-use a disk accessunit in which writing fails to complete in 300 msec or more because ofdisturbance or the like.

[0209] Operations for a situation that the recording and reproducingapparatus 1 reproduces AV data which are recorded in the magnetic diskmedium 20 will now be described.

[0210] Assume that AV data which have been already recorded in themagnetic disk medium 20 in the manner described above. As the recordingand reproducing apparatus 1 starts up, the file system 4 loads in thefile information, information regarding disk access units and the DAUconverting table 53 into a memory of the file system 4 from the magneticdisk medium 20.

[0211] The AV recording/reproducing HDD controller 3 makes an inquiry onthe number assigned to a disk access unit which needs be read next fromthe file system 4.

[0212] In response, the file system 4 notifies the AVrecording/reproducing HDD controller 3 of the number assigned to a diskaccess unit for which AV data are to be read from the file information.

[0213] Notified by the file system 4 of the number assigned to the diskaccess unit for which AV data are to be read, the AVrecording/reproducing HDD controller 3 makes an inquiry on an LBA at thetop of the disk access unit.

[0214] The file system 4, receiving the inquiry from the AVrecording/reproducing HDD controller 3, obtains the LBA at the top ofthe disk access unit denoted as the top LBA 55 according to the diskaccess unit number, using the DAU converting table 53 which is shown inFIG. 16, and notifies the AV recording/reproducing HDD controller 3 ofthe same.

[0215] Notified of the LBA, the AV recording/reproducing HDD controller3 designates the LBA and the number of sectors which amount to the sizeof the disk access unit and issues a read command to the file system 4,and the file system 4 relays thus sent read command to the HDD 2.

[0216] The HDD 2 converts the notified LBA into a track number and asector number with reference to the table which is shown in FIG. 17,reads AV data from sectors which form a corresponding track of themagnetic disk medium 44, and transfers to the AV recording/reproducingHDD controller 3.

[0217] The AV recording/reproducing HDD controller 3 transfers thus readAV data to the play buffer 9.

[0218] The play buffer 9 stores the AV data transferred from the AVrecording/reproducing HDD controller 3, and outputs stored AV data inreal time.

[0219] When a free space amounting to one disk access unit is createdwithin the play buffer 9, the AV recording/reproducing HDD controller 3is notified of that.

[0220] At the timing of the notification from the play buffer 9 of thefree space amounting to a disk access unit, the AV recording/reproducingHDD controller 3 issues a read command to the file system 4. Operationssimilar to those described above will be then repeated, thereby readingthe AV data one after another.

[0221] As described above, for reading of AV data, the error monitoringmeans 6 monitors whether a read command issued by the AVrecording/reproducing HDD controller 3 is executed normally or an errorhas occurred, and accordingly detects a defective disk access unit.

[0222] That is, FIG. 7 shows operations of the error monitoring means 6.The operations of the error monitoring means 6 will now be describedwith reference to FIG. 7.

[0223] When the AV recording/reproducing HDD controller 3 issues a readcommand in the manner described above (S1), the error monitoring means 6starts error monitoring. In other words, using the timer 7, an elapsedtime since the issuance of the read command by the AVrecording/reproducing HDD controller 3 is measured.

[0224] The error monitoring means 6 determines whether a notification ofend of read command has been sent from the HDD 2 (S2). When thenotification of end of read command is yet to be received from the HDD2, the error monitoring means 6 proceeds to S4, but to S3 when thenotification of end of read command has been sent from the HDD 2.

[0225] At S4, the error monitoring means 6 determines whether an elapsedtime since the issuance of the read command is 300 msec or more. Thetime 300 msec is a time over period which is yielded from the continuityof AV data. That is, in the event that reading ends in 300 msec orshorter time, it is possible to continuously reproduce AV data without abreak. A method of deriving the timer over period will be describedlater. When it is 300 msec or more since the issuance of the readcommand, the error monitoring means 6 proceeds to S5, but to S2 when itis 300 msec or shorter.

[0226] In the event that an elapsed time of 300 msec or more has elapsedsince the issuance of the read command, the error monitoring means 6 atS5 instructs the AV recording/reproducing HDD controller 3 to interruptthe reading. Provided with the instruction from the error monitoringmeans 6, the AV recording/reproducing HDD controller 3 issues a readinterrupt command to the file system 4, and the file system 4 relays theread interrupt command to the HDD 2. Receiving the read interruptcommand, the HDD 2 interrupts the reading and proceeds to S6.

[0227] At S6, the error monitoring means 6 notifies the skip processingjudging means 5 of detection of a defective disk access unit. The skipprocessing judging means 5, notified by the error monitoring means 6 ofdetection of a defective DAU, starts up skip processing. The skipprocessing will be described later.

[0228] Meanwhile, at S3, when notifying of the end of the read command,the HDD 2 also notifies whether the read command was ended normally orbecause of an error. Upon receipt of the notification of end of readcommand from the HDD 2, the error monitoring means 6 judges whether theread command was ended normally or because of an error. The errormonitoring means 6 proceeds to S6 after an error-induced termination,but to S7 after a normal termination.

[0229] When the read command was ended because of an error, or when theread command failed to end even after 300 msec or more, the errormonitoring means 6 decides at S6 that a read error has occurred, andjudges that the disk access unit from which reading of the AV data wastried is a defective disk access unit.

[0230] At S7, in the event that the read command was ended normally, theerror monitoring means 6 notifies the skip processing judging means 5 ofa normal termination of the read command, and the AVrecording/reproducing HDD controller 3 transfers AV data to the playbuffer 9 and issues the next read command when notified of outputting ofAV data amounting to a disk access unit from the play buffer 9.

[0231] Operations of the skip processing judging means 5 will now bedescribed. FIG. 9 shows operations of the skip processing judging means5.

[0232] At S20, when notified by the error monitoring means 6, the skipprocessing judging means 5 judges whether this notification is anotification of a normal termination of a read command or a notificationof detection of a defective disk access unit (S21).

[0233] When the notification is a notification of a normal terminationof a read command, the skip processing judging means 5 proceeds to S25,but to S22 when the notification is a notification of detection of adefective disk access unit

[0234] At S22, the skip processing judging means 5, notified by theerror monitoring means 6 of detection of a defective disk access unit,increments the read skip counter of this disk access unit only by 1 andproceeds to S23.

[0235] At S23, the skip processing judging means 5 judges whether thevalue of the read skip counter is over 5. The skip processing judgingmeans 5 proceeds to S24 when the value is over 5, but to S25 when thevalue is equal to or smaller than 5.

[0236] At S24, the skip processing judging means 5 turns on the bad DAUflag of this disk access unit and proceeds to S25.

[0237] At S25, the skip processing judging means 5 acquires the numberassigned to the disk access unit which needs be read next from the filesystem 4, decides that this is the current disk access unit, andproceeds to S26.

[0238] At S26, the skip processing judging means 5 judges whether thebad DAU flag of the current disk access unit is ON or OFF. That is, whenthe bad DAU flag of the current disk access unit is ON, the skipprocessing judging means 5 proceeds to S25. Meanwhile, when the bad DAUflag of the current disk access unit is OFF, the skip processing judgingmeans 5 notifies the AV recording/reproducing HDD controller 3 of thenumber assigned to the disk access unit whose bad DAU flag is ON, andproceeds to S27.

[0239] At S27, notified of outputting of AV data amounting to a diskaccess unit from the play buffer 9 and generation of a free spaceamounting to one disk access unit within the play buffer 9, the AVrecording/reproducing HDD controller 3 skips the disk access unit whichis covered by the notification from the skip processing judging means 5,acquires the number assigned to the disk access unit which needs bewritten next from the file system 4, and proceeds to S28.

[0240] At S28, the AV recording/reproducing HDD controller 3 issues aread command which is for reading AV data from the next disk access unitto the HDD 2 via the file system 4.

[0241] In this manner, the recording and reproducing apparatus 1 readsAV data from the magnetic disk medium 20 one after another.

[0242] As described above, during reading, when an error is created, therecording and reproducing apparatus 1 according to this embodimentincrements the read skip counter of the error-bound disk access unitonly by 1. As for a disk access unit for which the value of the readskip counter is over 5, the bad DAU flag of this disk access unit isturned on. Meanwhile, reading from a disk access unit whose bad DAU flagis ON is not executed.

[0243] Hence, during reading, too, unlike according to the conventionaltechnique, the recording and reproducing apparatus 1 according to thisembodiment is capable of continuously transferring AV data withoutexecuting replacement processing.

[0244] Operations for deletion of AV data which are recorded in themagnetic disk medium 20 will now be described.

[0245] AV data which are recorded in the magnetic disk medium 20 aremanaged as objects. That is, an object refers to AV data from pressingof a record start button of the recording and reproducing apparatusuntil pressing of a record stop button. During this, a pause button maybe used.

[0246]FIG. 12 shows operations for deleting an object which is recordedin the magnetic disk medium 20. A description will now be given withreference to FIG. 12.

[0247] At S40, the AV recording/reproducing HDD controller 3 initiatesdeletion processing. In short, the AV recording/reproducing HDDcontroller 3 acquires the number assigned to the disk access unit whichis to be deleted from the file system 4, and issues a delete commandwhich is for deletion of AV data which are recorded in this disk accessunit.

[0248] Receiving the delete command, the file system 4 initializes atable which is for associating the file to be deleted with the diskaccess unit, and writes in the HDD 2.

[0249] That is, this table contains the bad DAU flags, the skip countersand the like, and the file system 4 turns off the bad DAU flag (S41) andinitializes the read skip counter to zero (S42) during initialization ofthe table.

[0250] The write skip counter of the deleted disk access unit is notinitialized and left as it is. Hence, a disk access unit for which thevalue of the read skip counter is over 5 cannot be re-used even afterdeletion of AV data. On the contrary, a disk access unit for which thevalue of the read skip counter is equal to or smaller than 5 becomesre-usable after deletion of AV data.

[0251]FIG. 5 shows a magnetic disk medium as it is before deletion of anobject as the magnetic disk medium 20, while FIG. 6 shows a magneticdisk medium as it is after deletion of an object as a magnetic diskmedium 30.

[0252] An object 0 (24) and an object 1 (25) are recorded in themagnetic disk medium 20. Among disk access units in which the object 0(24) is recorded are the usable defective DAU 22;for which the value ofthe read skip counter is equal to or smaller than 5 and the unusabledefective DAU 23 for which the value of the read skip counter is over 5.

[0253] After deletion of an object, since the value of the write skipcounter of the usable defective DAU 22 is equal to or smaller than 5,the value of the read skip counter of the usable defective DAU 22 isinitialized to zero and the bad DAU flag of the usable defective DAU 22is turned off, the usable defective DAU 22 is re-used as denoted at ausable defective DAU 28 which is usable after deletion of an object. Onthe contrary, since the value of the write skip counter of the usabledefective DAU 23 is over 5 even after deletion of an object, the usabledefective DAU 23 is not re-used as denoted at an unusable defective DAU29.

[0254] Hence, disturbance such as vibrations will not cause adefect-free disk access unit to be treated as a defective disk accessunit permanently, and therefore, it is possible to re-use a defect-freedisk access unit.

[0255] While the foregoing has described recording of AV data andreproduction of AV data separately, the recording and reproducingapparatus 1 according to this embodiment is capable of reproducing AVdata which are recorded in the magnetic disk medium 20 whilesimultaneously recording AV data. In this manner, for reproduction ofalready recorded AV data while simultaneously recording AV data, the AVrecording/reproducing HDD controller 3, the error monitoring means 6 andthe skip processing judging means 5 perform the recording operations andthe reproducing operations described above in a time-shared manner.

[0256] As described earlier, a method of calculating 300 msec which isthe timer over period will now be described.

[0257] Assume that the recording and reproducing apparatus 1 accordingto this embodiment guarantees both the continuity of AV data to berecorded and the continuity of AV data to be reproduced in the eventthat one wishes to perform simultaneous recording/reproduction which isfor reproducing AV data which are recorded in the magnetic disk medium20 while simultaneously recording AV data, and guarantees the continuityof AV data even when defects occur in disk access units at a probabilityof 30% both during writing and reading.

[0258] Assume that the recording buffer 8 is capable of storing AV datawhich are equivalent to maximum of three disk access units and the playbuffer 9 is likewise capable of storing AV data which are equivalent tomaximum of three disk access units.

[0259] Assume that time needed to write in or read from a defect-freedisk access unit is 160 msec. Assume also that time needed to output orinput AV data which are equivalent to one disk access unit is 560 msec.

[0260] Under these conditions, 560×3 msec is time needed to store AVdata equivalent to three disk access units in the recording buffer 8 ortime needed to output AV data equivalent to three disk access units fromthe play buffer 9. Where the timer over period is Tout, time for readingfrom three disk access units and writing in three disk access units is160 msec×3×2+(Tout−160)×3×0.3×2. Since this period must be shorter thanthe time for storing AV data equivalent to three disk access units inthe recording buffer 8 or the time for outputting AV data equivalent tothree disk access units from the play buffer 9 in order to guarantee thecontinuity of AV data, the relationship expressed as Formula 1 belowmust be satisfied:

160×3×2+(Tout−160)×3×0.3×2<560×3)   (Formula 1)

[0261] From Formula 1, Tout must satisfy Formula 2 below:   (Formula 2)

Tout <560  (Formula 1)

[0262] Further, the relationship expressed as Formula 3 must besatisfied, in order to guarantee the continuity of AV data in the eventthat timeout occurs once each during writing and reading when AV dataequivalent to three disk access units are written while simultaneouslyreading AV data equivalent to three disk access units.

160 msec×2×2+Tout×2<560×3  (Formula 3)

[0263] From Formula 3, Tout must satisfy Formula 4 below:   (Formula 4)

Tout<520 msec  (Formula 3)

[0264] Hence, the timer over period needs be set shorter in a situationthat timeout occurs once each during writing and reading.

[0265] Further, when retry processing, which is for reading from a diskaccess unit once again, is to be executed only once in response totimeout occurring during reading, Formula 5 must be then satisfied:

160 msec×2×2+Tout×3<560×3  (Formula 5)

[0266] From Formula 5, Tout must satisfy following Formula 6.

Tout<347 msec  (Formula 6)

[0267] Hence, when timeover occurs during reading, if reading from thatdisk access unit is to be permitted only once, the timer over period maybe set to 347 msec or shorter. Meanwhile, when Tout is set to 347 msecor shorter, it is possible to satisfy all conditions of Formula 1through Formula 6.

[0268] 300 msec which is the timer over period in this embodiment iscalculated through the consideration described above.

[0269] While the embodiment has been described in relation to therecording and reproducing apparatus 1 which uses the magnetic diskmedium 20, the embodiment may be a recording and reproducing apparatuswhich uses other recording medium.

[0270] For instance, FIG. 2 shows a recording and reproducing apparatus11 which uses a DVD RAM as a recording medium. Unlike the recording andreproducing apparatus 1 shown in FIG. 1, the recording and reproducingapparatus 11 comprises an AV recording/reproducing DVD controller 13 anda DVD RAM drive 12. The AV recording/reproducing DVD controller 13controls the DVD RAM drive 12 like the AV recording/reproducing HDDcontroller 3 controls the HDD 2. Meanwhile, the file system 4 is similarto the file system of the recording and reproducing apparatus 1 exceptfor that this file system converts the number assigned to a disk accessunit into an LBA of a DVD RAM. The other blocks of the recording andreproducing apparatus 11 than those mentioned above are similar to thoseof the recording and reproducing apparatus 1. Thus, the embodiment maybe applied not only to a recording and reproducing apparatus which usesan HDD but to a recording and reproducing apparatus which uses a DVD aswell.

[0271]FIG. 3 shows a recording and reproducing apparatus 14 which uses amagneto-optic disk as a recording medium. Unlike the recording andreproducing apparatus 1, the recording and reproducing apparatus 14comprises an AV recording/reproducing DVD controller 16 and an MO drive15. The AV recording/reproducing DVD controller 16 controls the MO drive15 like the AV recording/reproducing HDD controller 3 controls the HDD2. Meanwhile, the file system 4 is similar to the file system 4 of therecording and reproducing apparatus 1 except for that this file systemconverts the number assigned to a disk access unit into an LBA of an MO.The other blocks of the recording and reproducing apparatus 14 thanthose mentioned above are similar to those of the recording andreproducing apparatus 1. Thus, the embodiment may be applied also to arecording and reproducing apparatus which uses a magneto-optic disk.

[0272] Further, although this embodiment requires that when a write orread command does not end even after an elapsed time of 300 msec or moresince the issuance of the command, the error monitoring means 6 notifiesthe skip processing judging means 5 of detection of a defective diskaccess unit, this is not limiting. The error monitoring means 6 maynotify the skip processing judging means 5 of detection of a defectivedisk access unit even in response to occurrence of a command error in anissued write or read command. A command error in this context is anerror which the HDD 2 notifies about within 300 msec, which is the timerover period, or in shorter time when the HDD 2 can not execute a writeor read command issued to the same for some reason, and such an erroroccurs in response to an ECC (error correction) error during reading orissuance of a command during initialization of the HDD 2.

[0273] A situation that a write error occurs according to the presentinvention is not limited to a situation that a write command fails toend even after an elapsed time of 300 msec or more since the issuance ofthe command: A write error referred to in the present invention may beone occurring in a situation that there is a notification ofincompetence of the HDD 2 of executing a write command within an elapsedtime of 300 msec or less since the issuance of the command, a situationthat recording of AV data in a disk access unit fails to complete evenafter the timer over period which is derived from the continuity of AVdata, or a situation that a command error occurs.

[0274] Further, although the foregoing has described that the skipprocessing judging means 5 turns on the bad DAU flag of the disk accessunit at S24 in FIG. 9 which shows the embodiment and proceeds to S25,this is not limiting. In other words, as shown in FIG. 10, the skipprocessing judging means 5 may turn on the bad DAU flag of the diskaccess unit at S24 and proceed to S24 a, and at S24 a, the skipprocessing judging means 5 may increment the write skip counter only by1 and then proceed to S25. Depending on the specifications of therecording and reproducing apparatus 1, despite a failure to normallywrite AV data in a disk access unit in reality, it may be judged thatthe writing has ended normally. In such a case, reading from the diskaccess unit will always result in an error. Hence, as shown in FIG. 10,execution of S24 a after S24 makes it possible to correctly judgewhether a disk access unit is permanently defective or not even when itis judged that writing has ended normally despite a failure to normallywrite AV data in the disk access unit in reality.

[0275] (SECOND EMBODIMENT)

[0276] A second embodiment will now be described.

[0277]FIG. 4 shows a recording and reproducing apparatus 17 according tothis embodiment.

[0278] The recording and reproducing apparatus 17 according to thisembodiment comprises a AV recording/reproducing HDD controller 18instead of the AV recording/reproducing HDD controller 3 of therecording and reproducing apparatus 1 according to the first embodiment.

[0279] Unlike the AV recording/reproducing HDD controller 3 according tothe first embodiment, the AV recording/reproducing controller 18 ismeans which controls the HDD 2 so that upon occurrence of an errorduring reading from a disk access unit, reading from the disk accessunit will be repeated until AV data stored in the play buffer 9 havebeen all outputted.

[0280] The others are similar to those according to the firstembodiment, and therefore, will not be described again.

[0281] Operations according to this embodiment will now be described.

[0282] Operations for recording of AV data are similar to thoseaccording to the first embodiment.

[0283] For reproduction of AV data, as in the first embodiment, theerror monitoring means 6 monitors whether an error has occurred duringreading.

[0284]FIG. 11 shows operations of the skip processing judging means 5. Adescription will now be given with reference to FIG. 11.

[0285] At S30, when notified by the error monitoring means 6, the skipprocessing judging means 5 judges whether this notification is anotification of a normal termination of a read command or a notificationof detection of a defective disk access unit (S31).

[0286] When the notification from the error monitoring means 6 is anotification of a normal termination of a read command, the skipprocessing judging means 5 proceeds to S37. When the notification is anotification of detection of a defective disk access unit, the skipprocessing judging means 5 proceeds to S32.

[0287] At S32, when notified by the error monitoring means 6 ofdetection of a defective disk access unit, the skip processing judgingmeans 5 increments the read skip counter of this disk access unit onlyby 1 and proceeds to S33.

[0288] At S33, the skip processing judging means 5 judges whether thevalue of the read skip counter is over 5. When the value is over 5, theskip processing judging means 5 proceeds to S34, but to S35 when thevalue is equal to or smaller than 5.

[0289] At S35, the skip processing judging means 5 makes an inquiryregarding whether the play buffer 9 is empty to the AVrecording/reproducing HDD controller 18. The AV recording/reproducingHDD controller 18, in response to the inquiry from the skip processingjudging means 5, checks the state of the play buffer 9 and notifies theskip processing judging means 5 of whether the play buffer 9 is empty.The skip processing judging means 5 proceeds to S37 when the play buffer9 is empty, but to S36 when the play buffer 9 is not empty.

[0290] At S36, the skip processing judging means 5 instructs the AVrecording/reproducing HDD controller 18 to read once again from theerror-bound disk access unit, and the AV recording/reproducingcontroller 18, instructed by the skip processing judging means 5, issuesa read command which is for reading from this disk access unit onceagain. The error monitoring means 6 monitors whether an error hasoccurred during this reading, as in the first embodiment.

[0291] At S34, since the value of the read skip counter is over 5, theskip processing judging means 5 turns on the bad DAU flag of the diskaccess unit and proceeds to S37.

[0292] At S37, the skip processing judging means 5 acquires the numberassigned to the disk access unit which needs be read next from the filesystem 4, decides that this is the current disk access unit, andproceeds to S38.

[0293] At S38, the skip processing judging means 5 judges whether thebad DAU flag of the current disk access unit is ON or OFF. That is, whenthe bad DAU flag of the current disk access unit is ON, the skipprocessing judging means 5 proceeds to S37. On the contrary, when thebad DAU flag of the current disk access unit is OFF, the skip processingjudging means 5 notifies the AV recording/reproducing HDD controller 18of the number assigned to the disk access unit whose bad DAU flag wasON, and proceeds to S39.

[0294] At S39, notified by the play buffer 9 of outputting of AV dataamounting to a disk access unit, the AV recording/reproducing HDDcontroller 18 skips the disk access unit which is covered by thenotification from the skip processing judging means 5, acquires thenumber assigned to the disk access unit which needs be written next fromthe file system 4, and proceeds to S40.

[0295] At S40, the AV recording/reproducing HDD controller 3 issues aread command which is for reading AV data from the next disk access unitto the HDD 2 via the file system 4.

[0296] In this manner, the recording and reproducing apparatus 1 readsAV data from the magnetic disk medium 20 one after another. Uponoccurrence of an error in a disk access unit, reading from the diskaccess unit will be repeated until the play buffer 9 has been emptied.

[0297] Hence, in addition to the effect according to the firstembodiment, it is possible to improve the reliability of reproduction ofAV data further more than in the first embodiment while continuouslyreproducing the AV data without a break.

[0298] The timer over period in the present invention is not limited to300 msec as in this embodiment, but may be any period of time, such as310 msec and 280 msec, which permits to guarantee the continuity of AVdata.

[0299] The skip counters according to the present invention are notlimited to the write skip counter and the read skip counter of theembodiment which are separately disposed for reading and writing, butmay be a counter which counts reading and writing altogether. In short,the skip counters according to the present invention may be any skipcounter which counts the number of times disk access units are skipped.

[0300] Further, the predetermined number of times according to thepresent invention is not limited to five times as in the embodiment, butmay be any number of times, such as four times and seven times, which isappropriate to judge that a disk access unit is permanently unnecessary.

[0301] Further, the recording medium in the present invention is notlimited to the magnetic disk medium 20 of the embodiment: Rather, therecording medium in the present invention may be any medium, such as amagneto-optic disk and an optical disk medium, which permits to recordor reproduce AV data.

[0302] Still further, the recording medium in the present invention maybe incorporated in the recording and reproducing apparatus according tothe present invention or freely attachable and detachable.

[0303] In addition, the present invention is directed to a program whichoperates in co-operation with a computer and which makes the computerexecute the functions of all or some means (or apparatuses, elements,circuits, parts, etc.) of the recording and reproducing apparatusaccording to the present invention described above.

[0304] Moreover, the present invention is directed to a medium which canbe read on a computer and stores a program, which operates inco-operation with a computer and which makes the computer execute thefunctions of all or some means of the recording and reproducingapparatus according to the present invention described above, and whichmakes said program as it is read operates in co-operation with saidcomputer and executes said functions.

[0305] In this context, some means (or apparatuses, elements, circuits,parts, etc. ) according to the present invention refer to some meansamong these plurality of means, or some functions in one means.

[0306] The present invention also covers a recording medium which storesthe program according to the present invention and can be read on acomputer.

[0307] In one example of use, the program according to the presentinvention may be recorded in a recording medium which can be read on acomputer so that the program operates in co-operation with the computer.

[0308] In one example of use, the program according to the presentinvention may be transmitted through a transmission medium and read by acomputer so that the program operates in co-operation with the computer.

[0309] The recording medium includes a ROM, etc., whereas thetransmission medium includes a transmission medium such as the Internet,light, an electric wave, a sound wave, etc.

[0310] As described above, the computer referred to in the presentinvention is not limited pure hardware such as a CPU but may includefirmware, OS, and further, peripheral equipment.

[0311] As described above, the structure according to the presentinvention may be realized by software or hardware.

INDUSTRIAL USE

[0312] As described clearly above, the present invention provides, arecording and reproducing apparatus, a recording and reproducing method,a medium and a program with which it is possible to continuouslytransfer AV data without a break without taking labor and time.

[0313] In addition, the present invention provides a recording andreproducing apparatus, a medium and a program with which it is possibleto continuously transfer AV data without deleting AV data which havealready been recorded in a recording medium.

[0314] Further, the present invention provides a recording andreproducing apparatus, a medium and a program with which it is possibleto continuously transfer AV data without decreasing an area which a usercan freely use.

[0315] Still further, the present invention provides a recording andreproducing apparatus, a medium and a program with which it is possibleto avoid permanently treating a defect-free disk access unit as adefective disk access unit due to disturbance such as vibrations and toaccordingly re-use a defect-free disk access unit.

1. A recording and reproducing apparatus, comprising: recording means which writes AV data in or reads AV data from a recording medium; and recording control means which, when there is a write error in writing of AV data in a disk access unit which is a minimum unit for continuously accessing said recording medium, controls said recording means such that this disk access unit will be skipped and said AV data will be written in the next disk access unit, wherein a replacement area which corresponds to said disk access unit in which there is said error is not formed in said recording medium.
 2. The recording and reproducing apparatus of claim 1, comprising error judging means which makes a judgment regarding whether said write error has occurred, wherein said recording control means controls said recording means based on said judgment.
 3. The recording and reproducing apparatus of claim 2, wherein said error judging means makes a judgment regarding whether there is a read error in reading of AV data from said disk access unit, and when there is a read error in reading of AV data in said disk access unit, said recording control means controls said recording means based on said judgment such that this disk access unit will be skipped and AV data will be read from the next disk access unit.
 4. The recording and reproducing apparatus of claim 2 or 3, wherein said error judging means judges that said write error or said read error has occurred when a command error occurs.
 5. The recording and reproducing apparatus of claim 2 or 3, wherein said error judging means judges that said write error or said read error has occurred when even after a timer over period derived from the continuity of AV data has passed, writing or reading of said AV data in said disk access unit fails to complete.
 6. The recording and reproducing apparatus of claim 5, wherein when writing or reading of said AV data in said disk access unit fails to complete even after said timer over period, said recording control means forcibly terminates a command issued to said recording means and accordingly controls such that said disk access unit will be skipped.
 7. The recording and reproducing apparatus of claim 1, comprising a write skip counter which counts the number of times that said disk access unit is skipped, wherein said recording control means controls such that when said number of times exceeds a predetermined value which is equal to or larger than 1, this disk access unit will not be used after this.
 8. The recording and reproducing apparatus of claim 7, wherein the number of times counted by said write skip counter is not initialized unless said recording medium is formatted.
 9. The recording and reproducing apparatus of claim 1, comprising a read protection flag which expresses whether to prohibit reading from said disk access unit, wherein when said read protection flag which corresponds to said disk access unit is ON, said recording control means controls such that reading from this disk access unit will not be executed, but controls such that reading from this disk access unit will be executed when said read protection flag which corresponds to said disk access unit is OFF.
 10. The recording and reproducing apparatus of claim 9, wherein when said write error has occurred during writing of said AV data in said disk access unit, said recording control means turns on said read protection flag which corresponds to said disk access unit.
 11. The recording and reproducing apparatus of claim 9, comprising a read skip counter which counts the number of times that a read error has occurred during reading of said AV data from said disk access unit, wherein when said number of times exceeds a predetermined value, said recording control means turns on said read protection flag which corresponds to said disk access unit.
 12. The recording and reproducing apparatus of claim 11, wherein when writing of said AV data in said disk access unit has ended normally, said recording control means turns off said read protection flag which corresponds to said disk access unit, and the value of said read skip counter which corresponds to said disk access unit is initialized to zero.
 13. The recording and reproducing apparatus of claim 11, wherein when said AV data recorded in said disk access unit are deleted, said recording control means turns off said read protection flag which corresponds to said disk access unit, and the value of said read skip counter which corresponds to said disk access unit is initialized.
 14. A recording and reproducing method, comprising: a recording step of writing AV data in or reading AV data from a recording medium; and a recording control step of, when there is a write error in writing of AV data in a disk access unit which is a minimum unit for continuously accessing said recording medium, controlling said recording step such that this disk access unit will be skipped and said AV data will be written in the next disk access unit, wherein a replacement area which corresponds to said disk access unit in which there is said error is not formed in said recording medium.
 15. The recording and reproducing method of claim 14, comprising an error judging step of making a judgment regarding whether said write error has occurred, wherein said recording control step controls said recording step based on said judgment.
 16. The recording and reproducing method of claim 15, wherein said error judging step makes a judgment regarding whether there is a read error in reading of AV data from said disk access unit is judged, and when there is a read error in reading of AV data in said disk access unit, said recording control step controls said recording means based on said judgment such that this disk access unit will be skipped and AV data will be read from the next disk access unit.
 17. The recording and reproducing method of claim 15 or 16, wherein said error judging step judges that said write error or said read error has occurred when a command error occurs.
 18. The recording and reproducing method of claim 15 or 16, wherein said error judging step judges that said write error or said read error has occurred when even after a timer over period derived from the continuity of AV data has passed, writing or reading of said AV data in said disk access unit fails to complete.
 19. A medium which can be processed on a computer and which stores a program for making a computer function as all or some of: recording means of the recording and reproducing apparatus of claim 1 which writes AV data in or reads AV data from a recording medium; and recording control means of the recording and reproducing apparatus of claim 1 which controls said recording means which, when there is a write error in writing of AV data in a disk access unit which is a minimum unit for continuously accessing said recording medium, controls said recording means such that this disk access unit will be skipped and said AV data will be written in the next disk access unit.
 20. A program for making a computer function as all or some of: recording means of the recording and reproducing apparatus of claim 1 which writes AV data in or reads AV data from a recording medium; and recording control means of the recording and reproducing apparatus of claim 1 which controls said recording means which, when there is a write error in writing of AV data in a disk access unit which is a minimum unit for continuously accessing said recording medium, controls said recording means such that this disk access unit will be skipped and said AV data will be written in the next disk access unit. 